Method and means for reproducing pictures



NOV. 7, 1939. WASHlNGTON' JR 2,179,002

METHOD AND MEANS FOR REPRODUCING PICTURES Filed March 4, 1936 2Sheets-Sheet l n W k WWI M,

' \lillllllllllllllwm GEARING us mmlunn WWI I l I N V EN TOR. M ll lm md George h asbllyfomfr 7 1939- G. WASHINGTON, JR 2,179,002

METHOD AND MEANS FOR REPRODUCING PICTURES Filed March 4, 1936 2Sheets-Sheet 2 T0 CURRENT SUPPLY George washingcon, Ir.

(Ittorneg ?atented Nov. 7, 1939 UNITED STATES George Washington,

Application March 4,

Glaims.

This invention relates to a method and machine for making reproductions,such as printing plates and mats for use in forming printing pressmatrices, directly from. a picture, form letter, map,

drawing, etc., as well as from an ordinary black and white or coloredphotograph or transparency.

it has heretofore been proposed to have a cut= ting tool cut impressionsin a printing plate directly, the amount of cutting being controlled bythe amount of light reflected from a picture to be reproduced. This,however, is not a practical method for the reasons that the cutting toolleaves ragged edges in the print plate and also because the tool verysoon becomes dull and the dull tool compresses the material to causebuckling of the plate. Furthermore, in order that the image shall befaithfully reproduced in the print plate it is necessary to make a largenumber of minute cuts at high speed, on the order of 600 per second, andat this speed the print plate material becomes soft and is displaced togive unevennesses which spoil the matrix. it is a principal object of myinvention, therefore, to provide an entirely new method for impressingthe image on the print plate, said method consisting in. destroying thematerial of which the print plate is composed rather than cutting orcompressing the same.

It is a further object of my invention to provide a novel method forreproducing a transpan ency, said method consisting in passing lightthrough the transparency.

It is a further object of my invention to form directly from a picture amat from which a printing press matrix may be formed directly.

It is a further object of my invention to provide a novel method andmeans for reproducing colored pictures, whether opaque or transparent.

Further objects and advantages of this invention will become apparent inthe iollowing detailed description thereof.

In the accompanying drawings:

Fig. l is a plan view with parts broken away disclosing an assembly ofthe mechanism constituting one form of my invention.

Fig. 2 is an end view with parts removed, disclosing the principalelements of the Fig. 1 device.

Fig. 3 is a wiring diagram illustrating the method of heating theimage-impressing point.

Fig. 4 is a view, partly sectioned vertically, of a dynamic unit.

Fig. 5 is a series of diagram illustrating the theory of operation ofcertain of the mechanism.

Jr... Morristown, N. 3.

1936, Serial No. 6?,123

(El. flit-l3) Fig. 6 is a plan view showing a modified light system.

Fig. 7 is a view similar to Fig. 6 disclosing utilization of a prism foruse in color reproduction.

The mechanism which is illustrated in the drawings and which constitutesone embodiment of my invention, consists primarily of two fundamentalparts, namely a fixed base-plate ill and a movable carriage l l mountedto slide on guides or runners l2. Upon the fixed base-plate ill there ismounted the driving mechanism consisting of a motor M which rotates twocylinders 29 and it in one-to-one relationship through reduction gearingsuch as that contained in reduc tion gear box 2i and driving a pair ofgears 22, 23 fixed to the shafts 25 upon which the cylinders 2i? and 2@,respectively, are mounted. The said shafts 2d, 25 are journalled inbracket 26 supported on base-plate it. The shaft 25 may he additionallysupported at its opposite end in bracket 2i, also fixed to thebase-plate id.

The picture, printed matter or other representation 3c is wrapped aroundthe cylinder 2G and held thereon by any suitable clamping means (notshown), and the printing plate 36' is wrapped around cylinder 2!) andfixed thereon by any suitable clamping means (not shown). There willfirst be described the reproduction of the picture til upon the printplate or matrix St in the case where the picture is a black and whitetransparency. For this purpose the cylinder 29 is a hollow transparentcylinder, preferably of glass, as shown, and a beam of light is designedto be reflected through the wall of the cylinder on to the surface ofthe transparency 39 so that the amount of light which passes through thetransparency will vary in accordance with the opacity of that point. Forthis purpose, there is mounted upon the carriage ii a source of light Lprovided with an optical system 3! designed to cause a beam of light tobe thrown upon a con denser lens 32, which converges the beam upon amirror 33 fixed in a sleeve 34 slidable within the hollow cylinder 20.The said sleeve 31 is provided with a cut-out portion 35 through whichthe reflected beam of light may pass. The optical system is such thatthe beam of light is focused at 36 upon the transparency 30. The amountof light passing through the transparency depends upon the opacity ofthe transparency at that point, and the quantity of light so determinedis caused to be transmitted into a lens system Bl where by suitableoptical system the light is focused upon a. light-sensitive cell 38 tovary the amount of current which passes through the cell. This currentafter being suitably amplified by any standard amplifier may be causedto operate a dynamic unit 28 as shown in Fig. 1 and in greater detail inFig. 4, to cause the armature 89 thereof to be repelled to a greater orlesser extent to cause a needle or tip 40 normally lying closelyadjacent to the surface of the print plate or matrix I! to be pressedinto said print plate to a greater or lesser degree depending upon thequantity of light that has passed through the corresponding point of thetransparency 30. The position of point I may be controlled by adjustingthe dynamic unit which is mounted on the carriage on guide rods 2! formovement toward or away from roller The dynamic unit may be fixed inposition by any suitable clamping means (not shown).

Instead of point ll being a cutting tool or a compressing tool, each ofwhich is subject to the defects already noted, namely uneven edges,buckling, etc., I provide means whereby the tip lll actually destroysthe material of the print plate to a greater or lesser degree, dependingupon the'degree of movement of tip 40 into the print plate. Suchdestruction is preferably accomplished by heating the tip 40 inconjunction with the proper selection of material comprising the printplate 30' so that said material will be destroyed by heat. Thus I haveprovided a heating coll ll suppliedwith current from any suitable sourceof current, as shown in Fig. 3, preferably through a transformer 42, tocause the said tip M to be maintained at a temperature of at least 600or 700 degrees. The material comprising the plate 30' may be any kindthat will be decomposed by heat, and for this purpose a nitro-celluloidmatrix has been found satisfactory. Other means than heat may beemployed, as, for instance, an acid, such as sulphuric acid, which 40will decompose or destroy the material upon which it acts, and, ofcourse, other materials than nitrocelluloid, such as ethyl cellulose,benzyl cellulose, and collodion, may be utilized provided they aredecomposed or destroyed by the tip 40. The essential difference frommethods heretofore employed is that instead of merely removing thematerial, it is disintegrated by any of the methods already mentioned,that is, heat or chemical action. The point 43 of tip I0 is conical,tapering toward the print plate, so that the degree to which the saidpoint enters the matrix will control the amount of material which isdecomposed and removed. There is thus formed in the plate a hole whosemagnitude is a function of the amount of light which has passed throughthe corresponding point of the transparency 30. The maximum actuation oftip 40 is such that the holes in adjacent rows (formed as describedbelow) just touch (as shown in Fig. 5).

It will now be apparent that if the light from light source L can befocused at a sufficiently large number of points on the surface oftransparency l0, and the cone tip 40 can be caused to remove material atcorresponding points on print plate 30 in proportion to the lightpassing through said points on transparency 30, then there would beobtained upon the printing plate 30' a reproduction of the picture orimage on the transparency 30. It will, of course, be an preciated thatthe greater the number of points and the closer they are located, thebetter will be the reproduction on the print plate ill. Foraccomplishing this purpose I provide means for causing the spot of light36 to traverse a spiral path of very fine pitch completely covering theunit and the tip surface of transparency 30. Also I provide for breakingup this light image so that it will strike the transparency 30 as asuccession of spots instead of in the form of a continuous beam. Thespiral path of light-spot 36 is eil'ected by causing the carriage llupon which the source of light L, optical system II and sleeve I withits optical systems 82 and II are mounted, to be moved in translationwhile the sleeve 34 is rotated. The translatory movement of carriage Hupon baseplate ll may beeifected from reduction gearing 2i drivingthrough gears 22, 28 to further reduction gearing 44, I to rotate shaft48 Journalled within the standards 20 and 21, to rotate a worm 41. Thesaid worm is threaded through a bearing 40 fixed to the carriage H sothat as the worm rotates the carriage is moved in translation. Thecarriage l I thus carries sleeve 34 in a linear direction within thehollow cylinder 20. The dynamic 40 being supported on carriage H aremoved correspondingly in translation.

At the same time that the sleeve 34 is being moved in translation, thecylinder 20 is being rotated, as hereinbefore described. Therefore thepoint of light I traverses a spiral path on the surface of transparency30. At the same time the tip 40 moving in translation and the cylinder20' rotating, causes the tip 40 to traverse a spiral path on the printplate ll in synchronism with the spiral path traversed by point of light36. g In order to break up the light striking the transparency 30 into aplurality of closely positioned points, there is provided a shutter III,shown also in Fig. 2, having a plurality of openings 5| which aredesigned to be successively brought into cooperating relation with thelight beam from source L. Thus, as each opening II moves into positionin front of the light beam, light will be flashed into the tube 20 andthen cut oil. as the said opening passes beyond said light beam. As thenext opening 5| moves into position, another flash of light is passedinto the hollow cylinder. The shutter 50 may be driven from the motor Mthrough the reduction gearing 2| by any suitable means such as a selsynsystem comprising a transmitter 52 and a receiver 53, the shutter 50being fixed to the shaft 54 of receiver 53. The said shaft may bemounted in a bracket III which also supports the sleeve 34 at I itsouter end.

Preferably, the cross section of tip 40 is made of the same shape as thecross-section of the beam of light striking the photo-cell 38. This isefl'ected by positioning a diaphragm 6B in advance of the photo-cell,said diaphragm being opaque except for an aperture N. If said apertureis circular, the cross-section of tip 40 is circular, and if theaperture is hexagonal, then the cross-section of tip III is likewisehexagonal.

Preferably, the reduction gearing between motor M and cylinder 20 isdifferent from the reduction gearing between motor M and selsyntransmitter 52 by a slight amount sufficient to cause the light-spots ontransparency 30 in adjacent rows to be slightly displaced, preferably byhalf a diameter of a maximum light-spot, as shown in the second andthird diagrams of Fig. 5 whereby it will be seen that closer positioningof the adjacent rows of light-spots may be obtained. If the shutter illrotated in relation to cylinder 20 such that the revolutions of shutter50 were in one-to-one relation to cylinder 20 or an even multiple ordivision of the rotation of cylinder 20, then the light-spots inadjacent rows would always be side by side as shown in the first diagramof Fig. 5, whereas, if the rotation of the shutter 50 is caused to beslightly displaced from one-toone or from an even multiple or divisionof said rotation or cylinder 20, then the light-spots in adjacent rowswould be displaced.

The matrix or print plate 30' thus obtained may be used directly forprinting purposes. If the transparency is a positive, then the surfaceof the print must be used as the vehicle for the ink and the finishedprint will be a positive If the transparency is a negative, then thegraves become the vehicle for the ink.

While I have described the mechanism as consisting of two separatecylinders and 20', one to carry the original subject and the other tocarry the plate, it is obvious that I may utilize but one cylinder andmount the original and the plate side by side on said cylinder. Twoseparate cylinders, however, permit the reproduction of larger prints.

While I have described my invention above as applied to a transparency,it will be apparent that it is equally applicable for the making ofprinting plates for reproducing opaque pictures and printed subjects.Thus, in Fig. 6, it will be seen that the only change necessary to adaptmy invention for use with opaque pictures is to cause the light fromsource L to strike on the upper surface of opaque sheet from which itwill be reflected into the micro-tube 81. Everything else remains thesame. The light source L, the shutter 50, and the driving mechanismtherefor, are all mounted on carriage ii to be moved in translation asbefore, and the operation in every respect remains the same. The imagereproduced on print plate 30' in this case being a positive, the ink isapplied to the surface and not to the graves.

In a further modification of my invention :1 provide a method wherebyreproduction in natural colors may be made of colored subjects, saidsubjects being either transparencies or opaque. I shall first illustratethis form of my invention with relation to a colored transparency. Saidtransparency is wrapped around the cylinder 20 and the entire processtakes place as before with the following changes: For each coloredtransparency 30 I make a plurality of separate print plates 30'. Inmaking the first of said print plates 1 interpose between the lightsource L and the photo-cell a colored filter F as shown in Fig. i. Thisfilter may, for instance, be a red filter and therefore only the redparts of the transparency 30 will be transmitted to the print plate 30.In a screen plate colored transparency the image is formed by a silverdeposit on a colored screen. This deposit affects the magnitude of aflux while the color of the screen affects the quality. In other words,the light fiux passing through the colored screen plate 30 first isreduced by the opacity of the silver deposit and is then further reducedby the filtering action of the color of the screen. Thus, with the redfilter interposed in front of the light source, only the red in thecolored transparency will be reproduced in graves in plate 30 inaccordance with the intensity of the silver deposit. Similarly, a secondprint plate 30 may be made with a green filter inter posed in front oflight source L, and finally a third. print plate 30' may be made with ablue filter in front of light source L. In reproducing the picture,three separate printing operations are superimposed one upon the other,each printing operation utilizing one of the three print plates 39'.Each of these plates is engraved for one color element of the coloredtransparency. Let us take the plate on which the blue element has beenengraved. The original surface represents all the color elements (red,green, blue). All the surface for the blue has been engraved or removed,and, therefore, the remaining surface represents the red "and greenelements. Inasmuch as red and green are complementary to blue, theresultant color is yellow, and, therefore, this plate becomes the yellowprinter. In the same manner the red element plate becomes the blue-greenprinter and the green element plate, the magenta printer.

Taking the yellow, blue-green and magenta printers and covering theirrespective surfaces with the proper colored ink in such a manner that noink enters in the graves, the ink is transferred to paper bysuper-imposition, therefore a colored print results similar to thetransparency.

The printing of plates made from color separation negatives must be donein a different manner from those made from color transparencies, becausethe color separation has already been made in the negatives. The opaqueportions of the negative represent the color element and the clear partsrepresent the complementary color. The light flux passing through theclear parts engraves the print plate and therefore the graves representthe complementary colors. In printing from such print plates, the gravesare filled with ink and the surface of the plate wiped clear. Then theink in the graves is transferred to the paper. The finished print will,therefore, appear the same as the original'subject.

If the member 80 is not a transparency, but an opaque sheet onwhich acolored picture is impressed and which it is desired to reproduce, thenthe reflection system shown in Fig. 6 is employed with a suitable filterinterposed. Also, instead of employing colored filters, I may interposea. prism P between the light source and the image 36 to produce aspectrum indicated diagrammaticaliy at S, Fig. 7. The prism may berotatably mounted at ill so that a selective portion of the spectrumcorresponding to the red, green and blue filters may be utilized asdesired.

In accordance with the provisions of the patent statutes, I have hereindescribed the principle and operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof,but I desire to have it understood that the apparatus shown is onlyillustrative and that the invention can be carried out by otherequivalent means. Also, while it is designed to use the various featuresand elements in the combination and relations described, some of thesemay be altered and others omitted within the scope of the claims withoutinterfering with the more general results outlined, and the inventionextends to such use.

Having described my invention, what I claim and desire to secure byLetters Patent is:

l. The method of making reproductions on printing plates directly fromthe subject to be reproduced, the material of said plates being adaptedto be decomposed by heat, said method consisting in scanning the subjectwith light, transforming into a plurality of electrical pulsations thevariations in light transmitted by the subject, operating an engravingtool in synchronism with said light, heating said tool to a degree suchthat rapid thermal decomposition of the material of the printing plateis eflected. when said tool comes in contact with said plate, andcausing the tool to penetrate said material to a degree corresponding tothe respective electrical pulsations.

2. A machine for making printing plates directly from a subject to bereproduced, comprising a printing plate, the material of said platebeing adapted to be decomposed by heat, supporting means for the subjectand the printing plate, a light beam cooperating with said subject, anengraving tool cooperating with said plate, means for heating said toolto a degree such that rapid thermal decomposition of the plate materialis efl'ected when said tool comes in contact with said plate, meanswhereby said light beam scans said subject, means for operating saidengraving tool in synchronism with said light beam, means fortransforming into a plurality of electrical pulsations the variations inlight transmitted by the subject, and means for causing said tool topenetrate the material of the printing plate to a degree. correspondingto the respective electrical pulsations.

3. A machine for making printing plates directly from a subject to bereproduced, comprising a printing plate, cylindrical supporting meansfor the subject and the plate, a light beam cooperating with saidsubject, means for causing said light beam to traverse a helical path toscan said subject, an engraving tool cooperating with said plate, meansfor heating said tool to a degree such that rapid thermal decompositionof the plate material is eiiected when said tool comes in contact withsaid plate, means for causing said tool to traverse a spiral path insynchronism with said light beam, means for transforming into aplurality of electrical pulsations the variations in light transmittedby the subject, and means for causing said tool to penetrate thematerial of 'the' printing plate to a degree corresponding to therespective electrical pulsations.

4. A machine for making reproductions on printing plates directly from atransparency,

, comprising a hollow light-transmitting cylinder for supporting thetransparency, a printing plate, means for supporting the printing plate,a light system for transmitting a light beam into said cylinder andiocussing said beam on said transparency, means for causing relativerotary and axial movement between said transparency and said light beamwhereby said beam scans said transparency, an engraving tool cooperatingwith saidplate, means for heating said tool to a degree such that rapidthermal decompositionof the plate material is efl'ected when said toolcomes in contact with said plate, means for causing relative rotary andaxial movement between said tool and said plate in synchronism with themovements of said light beam relative to said transparency, means fortransforming into a plurality of electrical pulsations the variations inlight transmitted by the subject, and means for causing said tool topenetrate the material of the printing plate to a degree correspondingto the respective electrical pulsations.

5. A machine for making printing plates directly from a subject to bereproduced, comprising a printing plate, cylindrical supporting meansfor the subject and the plate, a light beam coopcrating with saidsubject, means for causing relative rotary and axial movement betweensaid subject and said light beam whereby said beam scans said subject, ashutter, means for operating said shutter for periodically shutting oiland passing said beam, the movement of said shutter relative to therotary movement between said subject and said light beam being soadjusted that the points where the light beam strikes said subject inadjacent circumferential rows are relatively displaced, an engravingtool cooperating with said plate, means for heating said tool to adegree such that rapid thermal decomposition of the plate material iseffected whensaid tool comes in contact with said plate, means forcausing relative rotary and axial movement between said tool and saidplate in synchronism with the move-' ments oi! said light beam relativeto said subject, means for transforming into a plurality of electricalpulsations the variations in light transmitted by the subject, and meansfor causing said tool to penetrate the material of the printing plate toa degree corresponding to the respective electrical pulsations.

6. A machine for making printing plates directly from a subject to bereproduced, comprising a printing plate, supporting means for thesubject and the printing plate, a light beam cooperating with saidsubject, an engraving tool cooperating with said plate, means forheating said tool to a degree such that rapid thermal decomposition ofthe plate material is effected when said tool comes in contact with saidplate, means whereby said light beam scans said subject, a shutter,means for operating said shutter for periodically shutting oil andpassing said beam, means for operating said engraving tool insynchronism with said light beam, means for transforming into aplurality oi electrical pulsations the variations in light transmited bythe subject, and means for causing said tool to penetrate the materialof the printing plate to a degree corresponding to the respectiveelectrical pulsations.

7. A machine for making reproductions on printing plates directly from asubject to be reproduced, comprising a printing plate, means forsupporting the subject and the printing plate, a light beam cooperatingwith said subject, a diaphragm having an aperture of predetermined sizeand shape through which said beam is adapted to pass, an engraving toolcooperating with said plate, means for heating said tool to a degreesuch that rapid thermal decomposition of the plate material is eflectedwhen said tool comes in contact with said plate, means whereby saidlight beam scans said subject, means for operating said engraving toolin synchronism with said light beam, means for transforming into aplurality oi electrical pulsations the variations in light transmittedby the subject, and means for causing said tool to penetrate thematerial 01' the printing plate to a degree corresponding to therespective electrical impulses, said tool being tapered toward theprinting plate and having a cross-section similar to the aperture insaid diaphragm..

GEORGE WASHING-ION, Ja.

